There are known apparatuses in the prior art to measure a tensile force within a material web or a material strand.
EP 0 621 469 B1 discloses a tensile force measuring device to measure tensile forces in continuously running materials, in particular material webs or threads. This tensile force measuring device is located on a fixed clamped shaft axis and comprises a clamping area with a massive closed ring with a penetration hole, and a bearing area that can move freely in relation to the shaft in the direction of force. The clamping area and bearing area are connected together by a flexible spring.
Concerning the massive, closed ring in the clamping area, this design requires very high manufacturing precision (e.g., very small manufacturing tolerances). In addition, it is difficult to mount the tensile force measurement device onto the shaft axis.